September 2, 1909I 



NA TURE 



297 



usually originate lysigetiously and the adjoining paren- 

 chymatous cells frequently grow in like thylloses ; although 

 not definitelv ascertained, it seems probable that the process 

 is pathological. Incidentally, the author traced a meri- 

 rematic zone which gives rise to a thickening of the stem, 

 s in Ruscus. The paper appears in the Sitziwgsherichtc 

 der kaiserUchen Akadeinic dcr Wissenschaften, Vienna 

 (vol. c.wii., part viii.). 



The first portion of a study of various morphological 

 features in the Umbelliferae is contributed by Dr. K. 

 Domin to the Bulletin International (1908), published by 

 the Academic des Sciences de I'Empereur Francois 

 Joseph I. Various interesting points are noted regarding 

 the seedlings, e.g. the tubular shape of the cotyledon 

 stalks in species of Ferula, the occurrence of so-called 

 monocotyledonous embryos as in Buniuni, and three coty- 

 ledons observed in various species of Eryngium. The 

 formation of the tuber in such genera as Smyrnium and 

 Bunium is traced to the hypocotyl, which also produces 

 roots above fhe tuber. The most important statement 

 refers to the stipules, which are stated to be universally 

 present and free in all species of Hydrocotyle ; Schizeilema 

 and Huanaca possess adnate stipules, while species of 

 Bowlesia show various modifications from an ochrea to 

 laciniate appendages. 



The chief of the U.S. Meteorological Service decided 

 to make some important changes in the scope and character 

 of the Monthly Weather Review, beginning with July i. 

 The data are now grouped according to natural topographic 

 districts ; for this purpose the United States has been 

 divided into twelve climatological districts conforming to 

 its principal drainage areas, each being under the super- 

 vision of a selected division director. The Review is to 

 be devoted almost exclusively to the publication and dis- 

 cussion of climatological, river, and forecast data ; special 

 articles of a scientific nature, but not strictly climato- 

 logical, will be published in the Bulletin of the Mount 

 Weather Observatory or in separate form. The editors 

 (Messrs. Abbe and Abbe, jun.) will prepare, as hitherto, 

 brief notes on the progress of meteorological science 

 throughout the world, so that the Review may still mark 

 the development of the science, without publishing 

 extensively the details of meteorological papers. 



We have received a reprint of an article on " The 

 Tides: their Causes and Representation," published by 

 Mr. R. A. Harris in the June number of the Popular 

 Science Monthly. The article is illustrated by useful charts 

 showing the co-tidal lines in the different oceans. 



A NEW rainfall map of the Balkan peninsula, compiled 

 by Herr Franz Trzebitzky, appears in the August number 

 of Petermann's Mitteilungen. The data are obtained from 

 380 stations, 95 in Croatia and Dalmatia, 93 in Bosnia 

 and Herzegovina, 50 in Servia, 105 in Bulgaria, i in 

 Montenegro, 12 in Turkey, and 24 in Greece. The 

 averages are reduced to the period 1894-1905. 



The Zeitschrift of the BerUn Gesellschaft fiJr Erdkunde 

 (1909, p. 361) publishes a lecture delivered before the 

 society by Prof. Hecker on the determination of the value 

 of gravity and its application to the problem of the dis- 

 tribution of mass in the earth's crust. A general outline 

 of modern methods is given, and a summary of the most 

 important results obtained from observation. 



The Mitteilungen of the Vienna Geographical Society 

 (1908, p. 150) contains a very interesting and suggestive 

 paper by Dr. Max Muller on the graphical solution of a 

 number of problems in " astronomical " geography. Some 

 ten important problems are fully discussed, and methods 

 of solution with the help of rule and compasses alone 

 NO. 2079, VOL. 81] 



described. .\ final example shows how to determine the 

 approximate latitude and longitude of a place, from two 

 observations of the sun's altitude, using a large globe. 



Prof. Hammer, discussing a paper on the forty-ninth 

 parallel by Dr. Klotz (Journal of the Royal Astronomical 

 Society of Canada, 1908, p. 282), deals with the deter- 

 mination of the boundary line between Canada and the 

 United States west of the Lake of the Woods in a note in 

 Petermann's Mitteilungen (viii., p. 188). The extra- 

 ordinary difficulties inherent in the accurate laying down 

 of a parallel of latitude are dwelt upon with great 

 emphasis. 



The director-general of the Egyptian Survey Department 

 has issued a reprint of a technical lecture — one of a series 

 of such lectures — by Mr. J. I. Craig, on map projections. 

 The general principles of the subject are outlined, and 

 examples given of projections employed for different kinds 

 of maps. The construction of a network for a special 

 purpose is illustrated in an extremely interesting manner 

 by a " Mecca azimuthal " projection, which is designed to 

 give the true bearing of Mecca from every point of the 

 map. As the author remarks, " its usefulness in finding 

 the direction of the Qibla is evident." 



The June number of the National Geographic Magasine 

 contains an article by Mr. Charles E. Fay on " The 

 World's Highest Altitudes and First Ascents," which is 

 accompanied by some remarkably beautiful illustrations. 

 Mr. Milnor Roberts describes the Mount Rainier National 

 Park in an article entitled " A Wonderland of Glaciers 

 and Snow," and an interesting table, compiled by Mr. 

 N. H. Darton, gives the highest point in each of the 

 States. Mr. Hugh M. Smith, deputy commissioner 

 of the U.S. Bureau of Fisheries, contributes a graphic 

 account of " Brittany, the Land of the Sardine." 



The Journal de Physique for August contains the address 

 delivered by Prof. Paul Janet to the Soci^t^ frani;aise de 

 Physique in .April, on the history and the present position 

 of the question of the fundamental electrical units. After 

 giving a brief history of the various commissions which 

 have dealt with the subject, he gives in detail the decisions 

 arrived at under the headings ohm, ampere, volt, and 

 states to what extent these decisions have been adopted 

 olTicially by the various Governments. He is of opinion 

 that the action of many of these Governments in adopting 

 particular numbers as official has been rather precipitate, 

 and would prefer them to wait until the institution of an 

 international electrical laboratory has permitted compari- 

 sons to be made between the electrical standards kept at 

 the various national laboratories. 



The second of a series of papers dealing with the pheno- 

 mena exhibited by electric arcs between metal electrodes 

 appears in the American Journal of Science for August. 

 It is by Messrs. W. G. Cady and G. W. Vinal, and treats 

 of the oscillations which, under certain conditions, can be 

 produced. If an electromotive force of several hundred 

 volts is connected through a variable resistance to an air- 

 gap having, say, a copper kathode and an anode of any 

 conducting material, and an arc, is started, on increasing 

 the resistance until the current falls to about 0-4 ampere 

 the arc begins to oscillate with a frequency which in 

 general lies between 1000 and 50,000 per second, and 

 finally, as the resistance in series is increased, becomes a 

 glow discharge or is extinguished. The authors explain 

 with the aid of the volt-ampere curve the conditions which 

 control the production of these oscillations, and give a 

 provisional theory which covers the phenomena observed 

 up to the present time. 



